Limitations and Exceptions: The 2007 Intergovernmental Panel on Climate Change's (IPCC) assessment report concluded that global warming is “unequivocal” and gave the strongest warning yet about the role of human activities. The report estimated that sea levels would rise approximately 49 centimeters over the next 100 years, with a range of uncertainty of 20–86 centimeters. That will lead to increased coastal flooding through direct inundation and a higher base for storm surges, allowing flooding of larger areas and higher elevations. Climate model simulations predict an increase in average surface air temperature of about 2.5°C by 2100 (Kattenberg and others 1996) and increase of “killer” heat waves during the warm season (Karl and others 1997).